Category: Design

One of my long-brooded project for GIMP was an extension management system. I had it for years (older message from me I found about this was back in 2013, just a year after I started contributing).
I finally started working on it a few weeks ago!

I actually have a looot of projects regarding extending GIMP: better plug-in API, bidirectional communication with GIMP core, even GUI hacking through plug-ins, why not! But the first issue was: installing plug-ins and resources suck right now!
Let me explain the plan of things to come further below, but first a bit of a reminder:

You can crowdfund ZeMarmot/GIMP!

Everything done so far and to be done only happen thanks to ZeMarmot project. This project is paying for GIMP development, since this is all done for us to improve our production pipeline.

Right now, we don’t even have enough monthly funding to pay a single person at minimum wage. Yet we managed to survive at 2 for years. We had times of slight depressions and burnouts. Actually we kind of always have these lately.

We hope to at least crowdfund enough to pay 2 salaries at minimum wages! That would require about 4 times our current monthly funding. This is why for once I decided to detail more of my development plans in advance (rather than in the end when it is done, as I remind we are major GIMP developers) and I start by the crowdfunding call rather than the technicals, because we really need you!

If you like how GIMP has improved lately, and want it to continue this way, can you help us? If yes, our project is being funded on the 2 following platforms:

What is an extension?

What I call an extension is anything which can be installed in GIMP. In my current development code, an extension can already pack:

plug-ins

brushes (core and MyPaint ones)

dynamics

patterns

gradients

palettes

tool presets

In the future, it could also be:

scripts

templates

themes

icons

… and whatever else data I may forget!

What is management?

What I call “management” is basically being able to:

Search for new extensions (made available in remote repositories);

install new extensions;

uninstall extensions;

disable extensions (make them inactive without full removal);

update extensions: when the extension creator makes a new version available, GIMP should tell you and give you the possibility to update in a single click.

You probably all have an idea how it would work. For instance your web browser (i.e. Firefox, Chrome, etc.) probably has extensions as well and you may have searched/installed some. Well basically I want the same thing in GIMP.
Until now, “installing” an extension in GIMP implied making a web search, finding some compressed archive (sometimes on shaddy websites) with weird instructions asking you to put and unzip files into some hidden folder on your disk. Sometimes it was working, sometimes not and usually many barely understood what one were asked to do. Well it sucked.

Extension creator point of view

If you create resources for GIMP, be them brushes, splash images or plug-ins, here is what you’ll get: we are going to set up a website where you can upload your extensions. We don’t know yet if we will recycle the old registry.gimp.org domain (now down) or set up a new one (extensions.gimp.org?). We’ll see.
The code for the website will be on gitlab.gnome.org, though right now the repository is empty (working on GIMP core side first) as I just requested for its creation a few days ago.

Technically an extension is mostly about just adding metadata to your data: an extension name, a description, even screenshots if relevant. Your website URL is also welcome, as well as your bug tracker URL, so that we can redirect people to you when your extension has problems (making your development more efficient). In my current implementation, I chose the AppStream format for the metadata, which is well known by Free Software developers, quite featureful and easy to write (we still have some details to figure out for Windows and probably non-Linux support in general, but I am confident this will go well). Metadata is the main component to be able to search and manage extensions correctly!

We are extending it a bit with a few tags so that you can describe what kind of data your extension provides. For instance, here is the skeleton for metadata of an extension which ships a set of brushes:

That’s it. You put the brushes inside a brushes/ subdirectory (this is what is described in the “GIMP::brush-path” key) and you are done.

GIMP point of view

One of the cool thing which could happen on GIMP side is that we may transform some of our core data and plug-ins into core extensions as well. This would have 2 direct consequences:

It will be possible to easily disable features or data you don’t care about. I read some people even went as far as deleting files to make their GIMP menus clearer by removing features one never use. Well now it should be unneeded.

Updates could happen out-of-releases: a release of GIMP is a lot of work and preparation. You noticed how now we do them faster now? Well this won’t stop. Nevertheless if we can also update a core extension in the extension repository, this would make our job easier, we could do less core GIMP releases, yet you would get even faster updates for all the small features out there.

What about security?

Well that’s the big question! Let’s be clear: currently security of plug-ins in GIMP sucks.

So the first thing is that our upload website should make basic file type checks and compare them with the metadata listing. If your metadata announces you ship brushes, and we find executables in there, we would block it.

Also all executables (i.e. plug-ins or scripts) would be held for manual review. That also means we’ll need to find people in the community to do the review. I predict that it will require some time for things to set up smoothly and the road may be bumpy at first.

Finally we won’t accept built-files immediately. If code is being compiled, we would need to compile it ourselves on our servers. This is obviously a whole new layer of complexity (even more because GIMP can run on Linux, Windows, macOS, BSDs…). So at first, we will probably not allow C and C++ extensions on our repository. But WAIT! I know that some very famous and well-maintained extensions exist and are compiled. We all think of G’Mic of course! We may make exceptions for trustworthy plug-in creators (with a well-known track record), to allow them to upload their compiled plug-ins as extensions. But these will be really exceptional.

Obviously this will be a difficult path. We all know how security is a big deal, and GIMP is not so good here. At some point, we should even run every extension in a sandbox for instance. Well some say: the trip is long, but the way is clear.

Current code

As said, I am already working on it. Current code can already load extensions, read the metadata, enable and disable the extensions. These are the bases. I still have a lot to do on the bases (for instance the plug-ins need some special-casing for enabling/disabling).

Then I will need to work on getting the extension list from repositories, and work on the web side (Patrick David should help me there, since you can recall he also made our new website and Pixls.us, the trendy community site for photographers using FLOSS).

I cannot say when this will end and I do other things in the same time (lately I have worked on improving GIMP code for HiDPI, and of course I need to work more on our animation plug-in; and much much more!). But I hope a releasable state should be done by end of the year. 🙂

Aryeom is quite an advanced computer worker, yet there are times when she is lost as everyone else. This is when I come and help her. That’s part of my job!

She used to set custom icons in her Projects/ folders to recognize various status (not started, in-progress, done projects…) as well as unique icons for particular projects (ZeMarmot!). In GNOME Files/Nautilus, changing the default icon for any file is very easily done by a right click > Properties, then choosing an image to make it an icon. This is a very cool process when done progressively (changing the icon of a project folder when it is added, in-progress or finished, for instance, which doesn’t happen every minute!).

Aryeom’s Projects/ folder with icons representing project status

Unfortunately Aryeom had the case when she relocated her icon folder to a better location. And then, disaster! The icons did not follow (they could have if they had been replicated as data somewhere, similarly to how thumbnails are saved in ~/.cache/thumbnails; here that could have been under ~/.config since you want to keep these as settings… it turns out they weren’t) and she suddenly got a Projects/ folder full of white squares instead of nice custom icons. Aryeom was pissed because she didn’t want to move back her custom icons folder to the old location, neither did she want to change manually each and every past project icon (she has a lot). So she just stopped marking project status with custom icons because while until now, that was an organization system she was really proud of, from this day on, she felt that became a waste of time.

Side note: that is one of these times when the software is actually working against the human being, instead of helping. This feature is cool, and some people want to use it. But then we are basically asking people to always keep the icon images to the same place, never reorganize, never rename, never move. If you ever do one of these actions, you lose your carefully organized icons (maybe hundreds through the years) in an instant with no easy way to salvage them.
This is just a note for people who will try to design a similar feature in the future: unless you don’t want people to use it, or only trained engineers who understand the inner-working of files and metadata, just think twice for the right implementation.

I didn’t do a thing about this problem for a few weeks, but today, I had a closer look. So it turns out that these icons are stored as GIO metadata. Not sure where this metadata is actually stored (well I didn’t search either!), but I found out how to query then change it.

Query the metadata: gio info /a/file/

Change it: gio set /a/file metadata::custom-icon "file://URI"

You’ll note that this path is set as a file URI, not as a shell path. And so I quickly set up a bash script (not bothering about any kind of portability, that was a quick and dirty script for single use) to quickly change all the folder icons with a single ./fixicons.sh ~/Desktop/Projects/* call. Here it is:

I wrote it down here in case that helps any of you! Of course, up to everyone to customize it appropriately (in particular the regular expression of the second sed, for the piece of the URI you want to transform).

I do quite regularly similar helping scripts, for myself, for Aryeom, sometimes just out of curiosity, other times to improve my daily digital work. Over the years, I have hundreds of such scripts, a pretty well set up environment (in some previous job, I was even doing some cool workshops for coworkers about customizing one’s working environment to automatize all the boring repetitive activities or the things you don’t want to remember).

Most of these scripts are not in a state to be “released” since they are just quick and dirty hardcoded stuff (rarely they would get so useful that I feel I should release them; that’s how crossroad initially started as just my script to cross-compile GIMP until it became a fully generic cross-compilation tool for any software, to crossbuild for Win32, Android, etc.).
So I figured that maybe I should try and give more of my scripts and tricks to the world other ways, at least as small posts through this website, if not as proper generic tools. 🙂

Lately a recurrent contributor to the GIMP project (Massimo Valentini) contributed a patch to support HGT files. From this initial commit, since I found this data quite cool, I improved the support a bit (auto-detection of the variants and special-casing in particular, as well as making an API for scripts).

So what is HGT? That’s topography data basically just containing elevation in meters of various landscape (HGT stands for “height“), gathered by the Shuttle Radar Topography Mission (SRTM) run by various space agencies (NASA, National Geospatial-Intelligence Agency, German and Italian space agencies…). To know more, you can read here and there.
HGT download source: https://dds.cr.usgs.gov/srtm/version2_1/(go inside SRTM1/ and SRTM3/ directories for respectively 1 arc-second and 3 arc-seconds sampled data)
You probably won’t find other links of interest since not everyone can do such data (not everyone has satellites!).

Here is what it can look like after processing: left is an image obtained from NASA PDF, and right is the same data imported in GIMP followed by a gradient mapping.

So the support is not perfect yet because to get a nice looking result, you need to do it in several steps and that involves likely a bunch of tweaking. My output above is not that good (colors look a bit radioactive compared to the NASA one!) but that’s mostly because I didn’t take the time to tweak more.

And so that’s why I am writing this blog post. Someone trying to import HGT files in GIMP may be a bit disconcerted at first (so I’m hoping you’ll find this blog post to go further). At first you’d likely get a nearly uniform-looking grey image and may think that HGT import is broken. It is not.

What’s happening? Why is the imported HGT all uniform grey?

GIMP by default will convert the HGT data into greyscale. That is not a problem by itself since we can have very well contrasted greys. But that doesn’t happen for HGT import. Why?

HGT contains elevation data as signed 16-bit integers representing meters. In other words, it represents elevation from -32767 m to 32767 m (with an exception for -32768 which means “void”, i.e. invalid data; since that’s raw data with minimum processing, it can indeed contain errors). Therefore once mapped to [0; 1] range, color 0 (pure black) is invalid, ]0; 0.5] is anything under water level and [0.5; 1] is above water elevation.

Considering that on earth, the highest point is Mount Everest at 8848m, when mapped to our [0; 1] range, we see it has value 0.635. So you can see the problem: most things on earth will be represented with greys really close to 0.5 and that’s why there is no contrast.

How to get nice colors and contrast?

There are several solutions, but the one proposed by the contributor was to use the “Gradient Map” plug-in. That’s a good idea. Basically you remap your greys from 0 to 1 into color gradients.
Now you can try to create a gradient by setting random stops through the GUI, but that will most likely be quite a challenge. A better idea is to do it a bit more “scientifically” (i.e. to use numbers, which you can also do through the GUI by using the new blend tool, though not as accurately as I’d like with only 2 decimal places). This is what did Massimo here by creating a gradient file which would map “magenta for invalid data, blue below zero, green to 1000 m, yellow to 2000m, and gray to white above“. From this base, I added a bit of random tweaking because I was trying to get an output similar to the NASA document (just for the sake of it), so you can get a look at how my own gradient file looks like. But if you are looking to, say, create a relief map with accurate elevation/color mapping, you’d prefer to stick by the number-only approach.

Then once you get your gradient “code”, copy it in a file with the extension .ggr inside the gradients/ folder of your GIMP config, and just use it when running “Gradient Map” filter.

Just to explain a bit the format: for each line, you get the startpoint, midpoint and endpoint coordinates (in the [0; 1] range), followed by 4 values for RGBA (also in [0; 1] range) for the startpoint then again 4 values for RGBA endpoint color. Then you get an integer for the blending mode (you likely want to keep it linear, i.e. 0, for a relief map), then the coloring value (leave it to 0 as well, which is RGB). Finally the last 2 integers are whether the startpoint and endpoint must be fixed colors, or correspond to foreground, background, etc. You will likely want to keep them as fixed colors (0).

where start is the start elevation and end the end elevation in [0; 1] range; and RsGsBsAs and ReGeBeAe are respectively the start and end gradient colors.

That’s how you can easily map the elevation into colors! I hope that’s clear! 🙂

Can’t we have nicer support with a GUI?

Yes of course. This was fun and cool to review then improve this feature, and we should not let quality patches rot in our bugtracker, but that’s not my priority (as you know) so I stopped improving the feature (if I don’t stop myself from all these funny stuff out there, when would I work on ZeMarmot?!).
I gladfully accept new patches to improve the support and have left myself 2 bug reports to leave ideas about how to improve the current tools:

Improve “Gradient Map” filter to provide on-canvas preview and editing, similarly to the blend tool, because I realize this filter is powerful but that is a bit of a pain to use right now (iterations of edit gradient, run the filter for test, cancel, again and again).

Map gradients directly from HGT import with preview and [0; 1] range remapped to elevation in meters in the dialog so that we don’t have to constantly recompute values back and forth and edit .ggr files by hand.

In the meantime, I leave this blog post so that the format is at least understandable and HGT import usable to moderately technical people. 🙂

That’s it! Hopefully this post will be useful to someone needing to process HGT files with GIMP and willing to understand how this works, until we get more intuitive support.

Note: this is a copy of a post initially posted on Patreon and Tipeee.

Splash of GIMP 2.9.6 by Aryeom

Last month, we released the third development version of GIMP, version 2.9.6, as preparation of the next stable version, GIMP 2.10.

Same as for previous versions, ZeMarmot project was one of the major contributors with 274 commits (out of 1885 total for this release) by Jehan, 4 by Aryeom (some icons, a new paint dynamics “Pressure Size” very useful for flat coloring, and the splash image for this development version), and even for the first time, 3 commits by Lionel, a board member of LILA association. Hence about 15% of GIMP 2.9.6 was brought to you by ZeMarmot! 🙂

To get some more insight, you can have a look at the official announcement. And if you want to get the full and accurate list of Jehan’s contributions in particular, it is available on the source repository.

Brought to you in 2.9.6 by ZeMarmot

made libgimp as thread-safe, which basically means simplify plug-in developer work to have plug-ins using several cores (now all desktop computers are multi-core);

display angles when drawing lines;

code review for WebP image support, as well as some improvements and fixes (and even a patch upstream on libwebp library);

capability to switch exclusive visibility of layers inside layer groups only with shift-click (feature requested and tested/used by Aryeom for a few months before adding it to GIMP);

contributing to the Darktable and RawTherapee developers efforts for our new “raw” plug-in allowing importing RAW files through these third-party software and into GIMP (GIMP project advocates for cooperation with other Free Software);

contribution to allow GIMP to follow GEGL multi-thread limit (once again to have a better usage of modern computer processors but now in GIMP core in particular);

various improvements of PDF support, in particular multi-page PDF export from layers (this is the part where Lionel from LILA made his first steps as a developer with Jehan’s help!);

code review and fixes for improved support of PCX images import and export;

capacity of plug-ins to be installed in their own subdirectory, which should in the long run allow to get rid of the “DLL hell”, in particular on Windows system, a very common issue where some plug-ins embed libraries breaking other plug-ins;

Flatpak for creators on Linux?

For the creators who use GIMP on a GNU/Linux operating system, you may have heard of Flatpak, the generic application package system. Since we also exclusively use Linux, it felt important that GIMP be available in a timely manner (with distribution package systems, it is not unheard of to have to wait months after actual release to get some new version!). We take the opportunity of the release of 2.9.6 to test a first public Flatpak package. Since we don’t have a stable server, we made it available to our Patreon and Tipeee contributors only for the time being, then will try and make it available for everyone very soon!

For information, Windows already has a GIMP 2.9.6 installer available; and a MacOS package should hopefully soon get uploaded (it will depends on this package maintainer who has some family priorities right now). These are not maintained by us. » See the download page! « 🙂

Thanks and “en route to GIMP 2.10”!

I hope you appreciate our contributions to GIMP! Know that these are all thanks to our contributors, be them Patreon or Tipeee, in previous crowdfundings or the ones who make direct donations.

It is not easy everyday because we seriously lack funding, and we have had some blues more than once. ;-(
Yet the many of you who never failed us and continue to support us give us some courage.
Thanks to you!

This is the second video to present GIMP Motion, our plug-in to create animations of professional quality in GIMP. As previously written, the code is pretty much work-in-progress, has its share of bugs and issues, and I am regularly reviewing some of the concepts as we experiment them on ZeMarmot. You are still welcome to play with the code, available on GIMP official source code repository under the same Free Software license (GPL v3 and over). Hopefully it will be at some point, not too far away, released with GIMP itself when I will deem it stable and good enough. The more funding (see in the end of the article for our crowdfunding links) we get, the faster it will happen.

Whereas the previous video was introducing “simple animations”, which are mostly animations where each layer is used as a different finale frame, this second video shows you how the plug-in handles animations where every frame can be composited from any number of layers. For instance a single layer for the background used throughout the whole animation, and separate layers for a character, other layers for a second character, and layers for other effects or objects (for instance the snow tracks in the example in the end of the video).

It also shows how we can “play” with the camera, for instance with a full cut larger than the scene where you “pan” while following the characters. In the end, we should be able to animate any effect (GEGL operations) as well. This could be to blur the background or foreground, adding light effects (lens flares for instance), or just artistic effects, even motion graphics…
All this is still very much work-in-progress.

One of the most difficult part is to find how to get the smoother experience. Rendering dozens of frames, each of these composited from several high resolution images and complex mathematical effects, takes time; yet one does not want to freeze the GUI, and the animation preview needs to be as smooth as possible as well. These are topics I worked on and experimented a lot too because these are some of the most painful aspect of working with Blender where we constantly had to render pieces of animation to see the real thing (the preview is terribly slow and we never found the right settings even with a good graphics card, 32GB of memory, a good processor, and SSD hard drives).
One of the results of my work in GIMP core should be to make libgimp finally thread-safe (my patch is still holding for review, yet it works very well for us already as you can see if you check out our branch). So it should be a very good step for all plug-ins, not only for animation only.
This allowed me to work more easily with multi-threading in my plug-in and I am pretty happy of the result so far (though I still plan a lot more work).

Another big workfield is to have a GUI as easy to use, yet powerful, as possible. We have so many issues with other software where the powerful options are just so complicated to use that we end up using them badly. That’s obviously a very difficult part (which is why it is so bad in so many software; I was not saying that’s because they are badly done: the solution is just never as easy as one can think of at first) and hopefully we will get something not too bad in the end. Aryeom is constantly reminding me and complaining of the bugs and GUI or experience issues in my software, so I have no other choices than do my best. 😉

You’ll note also that we work on very short animations. We actually only draw a single cut at a time in a given XCF file. From GIMP Motion, we will then export images and will work on cut/scene transitions and other forms of compositing in another software (usually Blender VSE, but we hear a lot more good of Kdenlive lately, so we may give it a shot again; actually these 2 introduction videos were made in Kdenlive as a test). Since 2 cuts are a totally different viewpoint (per definition), there is not much interest on drawing them in the same file anyway. The other reasons is that GIMP is not made to work with thousands of high-definition layers. Even though GEGL allows GIMP to work on images bigger than memory size in theory, this may not be the best idea in practice, in particular if you want fast renders (some people tried and were not too happy, so I tested for debugging sake: that’s definitely not day-to-day workable). As long as GIMP core is made to work on images, it could be argued that it is acceptable. Maybe if animations were to make it to core one day, we could start thinking about how to be smarter on memory usage.
On the other hand, cuts are usually just a few seconds long which makes a single cut data pretty reasonable in memory. Also note that working and drawing animation films one cut at a time is a pretty standard workflow and makes complete sense (this is of course a whole different deal with live-action or 3D animation; I am really discussing the pure drawn animation style here), so this is actually not that huge of a deal for the time being.

To conclude, maybe you are wondering a bit about the term “cel animation”. Someday I guess I should explain more what was cel animation, also often called simply “traditional animation” and how our workflow is inspired by it. For now, just check Wikipedia, and you’ll see already how animation cels really fit well the concept of “layers” in GIMP. 🙂

Have a fun viewing!

ZeMarmot team

Reminder: my Free Software coding can be supported in
USD on Patreon or in EUR on Tipeee. The more we get
funding, the faster we will be able to have animation
capabilities in GIMP, along with a lot of other nice
features I work on in the same time. :-)

Last week, the core GIMP team has been meeting for Wilber Week, a week-long meeting to work on GIMP 2.10 release and discuss the future of GIMP. The meeting place was an Art Residency in the countryside, ~50km from Barcelona, Spain, with pretty much nothing but an internet access and a fire place for heating. Of course, both Aryeom and I were part of this hacking week. I personally think this has been a very exciting and productive time. Here is our personal report (it does not include the full result for everyone, only the part we have been a part of).

Software Hacking, by Jehan

GIMP on Flatpak

I’ve wanted to work on an official Flatpak build for at least 6 months, did some early tests already back in September, but could finally make the full time only this week. The build is feature-complete (this was not the case of the original nightly builds of GIMP, used as tests by Flatpak’s main developer, back when it was still called xdg-app; also these incomplete builds seem to have not been available anymore for a few months now), or nearly (since some features are still missing in Flatpak).

I’ll talk more on this later in a dedicated post, detailing what is there or not, and why, with feedback on the Flatpak project.
Bottom line: GIMP will have an official Flatpak, at least starting GIMP 2.10!

“Heavy coding and arting going on at #WilberWeek” (photo by Mitch, GIMP maintainer)

Working on the help system, Windows build, and more…

I’ve also worked in parallel on some other topics. For instance I’ve made a new Windows build of GIMP to test a few bugs (with my cross-build tool, crossroad, which I hadn’t used for a few months!), fixed a few bugs here and there, and also spent a good amount of time working on improving language detection for the help system (in particular some broken cases when you don’t have exactly the same interface language as the help you downloaded, since we don’t have documentations for as many languages as we have GUI translations). This part is mostly not merged in our code yet because unfinished. But it should be soon.
All in all, that was 26 commits in GIMP (and 1 minor commit in babl) last week, and a lot more things started.

Art hacking, by Aryeom

Aryeom, ZeMarmot director, contributed a lot of smiles (as always), art and design. Since Mitch forgot our usual “Wilber Flag”, she quickly scribbled one on a big sheet of paper (see in video).

Aryeom drawing Wilber (photo by Schumaml)

Wilber Flag, by Aryeom

Apart from playing with Wilber stamps, created by Antenne Springborn, Aryeom also spent many hours discussing t-shirt and patch designs with Simon Budig. Here is one of her nice attempts for a very classy outlined-Wilber design:

Outlined-Wilber design by Aryeom

Funny story: she chose as a base a font called montserrat, without realizing that the region we were in at the time was called Montserrat as well. Total coincidence!

She has also been working on some missing icons in GIMP, for instance the Import/Export preferences icon.

And with time permitting, she scribbled various drawings on paper, because digital painting doesn’t mean you should forget analog techniques, right?

Social hacking: interviews and merchandise

Developer interviews

I have been wanting to bring a little more life to our communication ever since we got a new website for GIMP. We already produce more regular news. I wish we had even more. I also think we should even extend to community news. So if you’ve got cool events around the world involving GIMP, do not hesitate to tell us about them. We may be able to make it a gimp.org news when time permits.

Something else I wanted is showing the people behind GIMP: developers and contributors, but even the artists, designers and other creators making usage of GIMP as a tool in their daily creative process. I have talked about these interviews for a few months now, and Wilber Week was my first attempt to make them a reality. I interviewed Mitch, GIMP maintainer, Pippin, GEGL maintainer, Schumaml, GIMP administrator, Simon, a very early GIMP developer and Rishi, GNOME Photos maintainer and GEGL contributor.
All these interviews soon to be featured on gimp.org!

And that’s only a start! I am planning on interviewing even more contributors (developers and non-developers) and also artists. 🙂

Merchandising

We regularly have requests about t-shirts or other merchandising featuring Wilber/GIMP. So we sat down and discussed on what should be exactly GIMP’s official position on this topic. As you know, I, personally, am all for Libre Art, so this was my stance. And I am happy that we are currently willing to be quite liberal.

Yet we have a lot of values and that was our main concern: how nice is your design? Is your merchandising using good material? Is it produced with ecologically-conscious techniques? Do you give back to the community?… So many questions and this is why Simon Budig will work on a ruleset of what will be acceptable GIMP merchandising that we will “endorse”. Endorsement from the GIMP project will mean that we will feature your selling page link on gimp.org and also that you will be allowed to feature on your own page some “endorsed by GIMP” text or logo. I’ve been quite inspired by this system which Nina Paley uses for Sita Sings the Blues movie.

Well that’s the current status, but don’t take it as an official position and wait for an official news or page on gimp.org (as a general rule, nothing I write is in any way an official GIMP statement unless confirmed on the main website by text validated by peers).

Release hacking!

The one you’ve all been waiting for, so I kept it for the end, or close: what about GIMP 2.10 release? We finally decided that it is time to get 2.10 going. We still have a few things that we absolutely need to fix before the release, but the main decision is that we should stop being blocked by unfinished cool features.

We have got many very awesome features which are “nearly there”, but mostly untouched for years. Usually it means that it globally works but is either extremely slow (like the Seamless Clone or n-point deformation tools), or that it is much too instable (up to the crash), often also with unfinished GUI…
Well we will have to do a pass through our feature list and will simply disable whatever is deemed non-releasable. The code will still be here for anyone to fix, but we just can’t release half-finished unstable features. Sorry.
The good news is that it suddenly divides our blocker list by 10 or so! And that should make GIMP 2.10 coming along pretty soon.

But so what of all these cool features? Will we have to wait until GIMP 3 now? Not necessarily! We decided to relax the release rules, which come from a time where all free software released major versions with new features and minor versions with bug fixes only (some kind of semantic versioning applied to end software). So now, if any cool new feature comes along or if the currently deactivated features get finished, we are willing to make minor releases with them! Yes you read it well. This makes it much more exciting for developers since it means you won’t have to wait for years to see your changes in GIMP. But it also means that our contribution process gets much more robust to the unfinished-patch-dropping issue. Of course the libgimp API (used by plugins) still stays stable. Changes does not mean breaking stability!
This was also summed-up in an official gimp.org news recently.

I am so happy about this because I have been pushing for this change in our release process for years. Actually the first time I proposed this was in Libre Graphics Meeting 2014, Leipzig (as I explained in my report back then). I call it a rolling release, where we can release very regularly new stuff, even if just a little. This time though, the topic was brought up by Mitch himself.

People hacking

The conclusion of this week is that it was very nice. As Simon Budig put it in his interview: I mostly stay for the people. I think this is the same for us, and these kind of social events are the proof of it. The GIMP project is ­ — before all — made of people, and not just any people, even nice people! Such event is a good occasion for meeting physically, from time to time, and not just with pixels and bits exchanged through the internet.
We also spent a few hours visiting Barcelona, in particular Sagrada Familia, and doing a few hikes in Montserrat.

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Panorama shot featuring several members of GIMP and GEGL (photo by Aryeom)

Financial hacking: ZeMarmot

As a conclusion, we remind you that ZeMarmot would be the way for me to work full-time on GIMP software development! We could do nearly as much every week if our project had the funding which allowed us to sustain ourselves while hacking Free Software. So if you wish to see GIMP be released faster with many cool features, don’t hesitate to click our Patreon links (for USD funding) or the Tipeee one (EUR funding).

How are going your last days of 2016 so far? It’s been a strange year? Well let’s not diverge, and focus on ZeMarmot, then, shall we? First be aware that our dear Director, Aryeom Han, is getting a lot better. She was also really happy to get a few “get well” messages and say thanks. Her hand is still aching sometimes, in particular on straining or long activities, but on the whole, she says she can draw fine now.

Reminding the project

I will discuss below what was done in the last months, but first — because it is customary to do so at end of year — I remind that ZeMarmot is a project relying on the funding by willing individuals and companies, with 2 sides: art and software.

I am a GIMP developer, the second biggest contributor in term of number of commits in the last 4 years and I also develop a plugin for digital 2D animation with GIMP, which Aryeom is using on ZeMarmot. I want to get my plugin to a releasable state by GIMP 2.10.

Aryeom is using the software to fully animate, draw and paint a movie, based on an original story which I wrote a few years ago, about a marmot who travels the world for reasons you will know when the film will be released. 🙂 Oh and the movie will be Creative Commons by-SA of course!

Up to now, our initial crowdfunding (~ 14 000 €) has allowed to pay several months of salary to Aryeom. I have chosen to not earn anything for the time being (not because I don’t like being paid but because we cannot afford it with current funding). Some of it is remaining but is kept to pay the musicians.

Now we are mostly relying on the monthly crowdfunding through the Patreon (USD funding) and Tipeee (EUR funding) platforms. But all combined, that’s about 180 € a month, which amounts to barely more than a day of salary (and with non-wage labour costs, that’s not all of it for Aryeom). 1 day per month to make a movie, that’s far from enough, right?

My dream? I wish we could some day consider ourselves a real studio, with many paid artists, producing cool Libre Art movies going to the cinema (yes in my crazy dream, Creative Commons by-sa films are on the big screen!), and developers paid to improve Free Software so that our media-making ecosystem gets even better and for everybody to use!
But right now, that’s no more than an experiment mostly done voluntarily.

Do you like my dream? Do you want to help us make it real? You can by helping the project financially! It can be the symbolic coin as the bigger donation, any push is actually helping us to make things happen!

Not sure yet? Feel free to read more below and to pitch in at any time later on!

Note that not only the money but also the number of supporters is of great help since it shows supports to bigger funders; and for us that’s good for morale too! A good monthly crowdfunding can also help us find producers without having to abandon any of the social and idealistic aspects of the project (note that we have already been contacted by a production who were interested by the film after the crowdfunding but we refuse to compromise too much on the ideal).

The animation

We illustrated Aryeom’s work by 2 videos presenting extracts of her work-in-progress. In this first video, she shows different steps in animating a few cuts of the main character:

In this second video, we examine some cuts of another character, the Golden Eagle, main predator of the marmot:

There are a lot which can be said on these few minutes shown about the work of “animator”. Many pages of books on the art of animating life could be filled from such examples! We will probably detail these steps in longer blog posts but I will still explain the basics here.

Animating = giving life

Aryeom says it in the first video and you can see it in several examples in both videos. When your character moves from A to B, you are not just “moving” it. You have to give the impression that the character is acting on oneself, that it is alive, inhabited, in other words: animated.

This is no surprise one of the most famous book on animation is called “The illusion of life” (by Frank Thomas and Ollie Johnston), also the bedside book of Aryeom. Going this way has a lot of ramifications on the animator job.

Believable, not realistic

Before we continue, I have to make sure I am understood. Even though realistic animation is also a thing (Disney comes to mind), making a good animation is otherwise not necessarily about making it “realistic”, but instead about making it “believable”.

It is very common to exaggerate some movements for various reasons (often because it is funnier, but also sometimes because exaggerating it may sometimes look even more believable than the realistic version!), or the opposite (bypassing anatomically-correct movements). There are no bad reasons, only choices to achieve what you want.

Now that this thing is clear, let’s continue.

You can’t just “move an arm”

The very classical example beginners will be given is often: “lift your right arm up”. That’s it? Did you only move your arm and the rest of the body stayed unchanged? Of course not. To stay in balance, your body shifted to the left as a counterweight; the right shoulder lifted whereas the left shoulder lowered; and so on.
A lot of things will change in your body with this simple action. Even your feet and legs may move to compensate the shift of the center of gravity. As a consequence, you don’t “move your arm”, you “move your whole body” (in a configuration where your arm is up).

This is one of the first reason why to just move a single part in a body, you cannot reuse previous drawings and change just this part. No, you will properly redraw the whole body because if you are to fake life, you may as well do it well.

Note: when you say “animation” to computer people, their brain usually immediately wires to “interpolation“, which is the mathematics to compute (among other things) intermediate positions. Because of what I said above, in reality, this mathematical technique is barely used in traditional (even when digital) animation. It is used a lot more in vector and 3D animation, but its role should definitely be minimized compared to the animator work even on these fields. In vector/3D, I would say that interpolation only replaced the inbetweener role (some kind of “assistant” who draw non-keyframe images) from the traditional animation world.

Timing, silence and acceleration

You often hear it from actors, poets, writers, singers, anyone who gives some kind of life: the silence is as important as the noise for their art. Well I would also add the acceleration and the symmetrical deceleration.

You can see this well on this first example of the video 1 (at 0’41). Aryeom was unhappy with her running marmot which was nearly of linear speed. Marmot arrived too fast on the flower. Well he slowed down, but barely. Her finale version, Marmot would arrive much faster with a much more visible slowdown, making the movement more “believable” (we get to the bases!).

The eagle flight in video 2 (at 1’09) is another good example of a difficult timing as Aryeom went through 2 stages before finding the right movements. With the wrong timing, her flying eagle feels heavy, like it has difficulty to lift itself into the air (what she called her “sick” eagle in the video); then she got the opposite with an eagle she felt more sparrow-like, too light and easy-lifted. She was quite happy with the last version (obtained after 8 attempts) though, and in particular of this very last bit in the cut, when the eagle gets in glider mode. Can you spot it? This is the kind of difference which just lasts for a few hundredth of seconds, barely noticed, yet on which an animator can spend a significant amount of time.

Living still images (aka “line boil”)

A common and interesting effects you find in a lot of animation is about a shaking still image. You can see it in the second video (at 0’33), first cut presenting the proud eagle still on his mountain. Sometimes you want to show a non-moving situation, but just sticking to a still image feels too weird because in real life, there is no perfect stillness. Even if you make all efforts to stay still for a few seconds, you will imperceptibly move, right? So how do you reproduce this? The attempt to stay perfectly still while this being impossible? Well commonly animators will just redraw the same image several times because as much as you can’t stay still, you can’t draw perfectly identical images twice either (you can get very close by trying hard though) and you loop them.

You usually don’t do this for everything. Typically, elements of the background, you accept them to be still much more easily. But this is common for your living character or sometimes to pull main elements which you want to tick out of the background.

Avoiding cycles

Now, loops are very usual in animation. But the higher quality you aim for, the less you have loops. Same as stillness does not exist in life, you never repeat exactly the same movement twice. So even though loops seems to be the first thing many animators will teach (the famous “walking cycles”), you don’t actually use these in your most beautiful animations. When your main character walks, you will likely re-animate every step.

Of course, it is up to you to decide where to stops. Maybe for this flock of birds in the background, far away, just looping (and even copy-pasting the birds to multiply them!) may be enough. Though this is all a matter of taste, time, and money ready to spent on animator-time obviously.

Camera work

This part has not really started yet, even though it has already been planned (from the storyboard step). But since Aryeom started (first video at 1’06), let’s give some more infos.

Panning and tilting

In animation, where the movement is by essence 2D as well, these refers to respectively a horizontal and vertical camera movement. Why do I need to say “in 2D animation”? Because in more traditional cinema, these will rather correspond to a tracking shot done on rails, whereas panning and tilting refer to angle movements of a static camera. Different definitions for different references. Note that even though 3D animation could be using one or the others, they mostly kept the animation vocabulary.

This gives you a good hint on how characters and background are separately managed. If you have a character walking, you will usually create a single image of the background, much bigger than the screen size, and your camera will move on it, along with the character layers. With fully digital animation, this usually means working on image files of much higher sizes than the expected display size; in traditional physically-drawn animations, it means using very large papers (or often even sticking papers together). As an example, at a Ghibli exhibition, they would display the background for a flying cut of “Kiki’s delivery service” and it would take a full wall in a very large room.

Animation is a lot of drawing

I will conclude the section on animation by saying: that’s a bloody lot of drawing!

As you can see, Aryeom spends time redrawing the same cuts so many times to get the perfect movement that sometimes she becomes crazy and thinks that she is just drawing the wrong animal. The story about the pigeon is a true story and I am the one who told her to add it to the video because that was so funny. Some day, she comes to me and show me her cut she has been working on for days. Then she asks me: “doesn’t it look like a pigeon?”
Hadn’t I stopped her, she was ready to start over.

This is an art where you even draw again when you want to show stillness, and you forbid yourself from using too much shortcuts like using loops. So what do you want: you probably have to be a little crazy from the start, no? 😉

There are actually several “schools”, and some of them would go for simplicity, shortcut and reusage. Japan is well known for the studio Ghibli which goes the hard way as we do, but this is quite a contradiction in the country industry. The whole rest of Japan’s animation industry is based on animating as little as possible. Haven’t they proved so many times that it is possible to show a single still image for 30 seconds, add sounds and voices, then call it an animation?

Sometimes it is just a choice or a focus. Some animation films focus on design rather than believable movements, or scenario rather than wonderful images. For instance, I don’t think you can say that The Simpsons has a wonderful graphics appeal and realistic animation (they even regularly makes meta-jokes inside episodes about the quality of their animation!), but they have the most fantastic scripts, and that’s what makes their success.
So in the end, there is no right choice. Every one should just go the way they wish for a given project.

And this is the way we are going for ZeMarmot!

Music

Just a very short note on music. We have started working with the musicians, remotely and on a physical meeting on December 1st. We have a few extracts of “first ideas” but they won’t do justice to the quality of the work.

I think this will have to wait for much later.

Software

I went so long about animation that I hope I have not lost half of the readers already! If you are still reading, I’ll say what I worked on these last months.

GIMP

I am trying to do my share on GIMP, to improve it globally, speed up the release of 2.10 and because I love GIMP. So I count 259 commit authorship in 2016 (60 in the last 3 months) + 48 as committers only (i.e. I am not the author, but the main reviewer of a patch which I pushed into our codebase). I commented on 352 bug reports in 2016, making it a habit to review patches when possible.

I have a lot of projects for GIMP, some of the grander being for instance a plugin management system (to install, uninstall and update them easily from within GIMP, and a backend side for plugin developpers to propose extensions), but also a lot of ideas about the evolution of the GUI (this should be discussed topic-per-topic on later blog posts).

Also I have been starting to experiment with Flatpak so that GIMP can provide an official release for GIMP. For years, our official stance has always been to provide a Windows installer, a OSX package, and GNU/Linux… yeah grab the source and compile or use the outdated version from your package manager! I think this situation can be considerably improved with Flatpak and similar technologies which were born these years.

Animation in GIMP

As explained already, I took the path of writing it as a plugin rather than a core feature. Anyway GIMP is only missing a single feature which would make it nearly as powerful: bi-directional notification (basically currently plugins don’t get notified when pixels are updated, layers are renamed, moved or deleted, images closed…). That’s actually something I’d like to work on (I already have a stash somewhere with WIP code for this).

The animation plugin currently has 2 views:

Storyboard view

GIMP’s animation plug-in: storyboard view

This actually corresponds to the very basic animation logic of 1 layer = 1 frame, which is very common by people making animated GIF (or MNG/WebP now), except with a nice UI to set each image duration (instead of tagging the layer names, a very nasty user experience, feature hidden and found only on some forums or old tutorials), do basic compositing and even comments on vignettes if-need-be. All this with a nice preview in real-time!

Cel-Animation view

GIMP’s Animation plug-in: cel-animation view

This is the more powerful view where you can compose a frame from several images, often at least a background and a character. In the above example, the cut is made from 3 elements composed together: the background, the eagle and the marmot.

You may usually know more of the “timeline” style of view, which is basically the same thing except that frames are displayed as horizontal tracks. I tried this too, but quickly shifted to this much more traditional view in the animation world, which is usually called an x-sheet (eXposure sheet). I found it much more practical, allowing commenting more easily too, easy scroll, and especially more organized. There is a lot you don’t see in this screenshot, but this view is really targetting a professional and organized workflow. In particular with layers properly named, you can create animation loops and line tests of dozens of images, with various timings, in a few clicks.

I am also working on keyframing for effects (using animated GEGL operations) and camera movements.

Well there is a lot done but definitely a lot more I am planning to do there, which takes time. I will post more detailed blog posts and will push the code on a branch very soon (probably before Libre Graphics Meeting this year).

That’s all, folks!

And so that’s it for this end-of year report from ZeMarmot team! I hope you appreciate the project. And if so and can spare the dime (or haven’t done so yet), I remind the project accepts any amount on the links given above. Some people just give 1 Euro, others 15 Euro per month. In the end, you are all giving life to ZeMarmot!

I can try and do more coding, more code reviewing, revive designing discussions… that’s cool, yet never enough. GIMP needs more people, developers, designers, community people, writers for the website or the documentation, tutorial makers… everyone is welcome in my grand scheme!

Many of my actions lately have been towards gathering more people, so when I heard about the GNOME newcomers initiative during GUADEC, I thought that could be a good fit. Thus a few days ago, I had GIMP added in the list of newcomer-friendly GNOME projects, with me as the newcomers mentor. I’ll catch this occasion to remind you all the ways you can contribute to GIMP, and not necessarily as a developer.

Coding for GIMP

GIMP is not your random small project. It is a huge project, with too much code for any sane person to know it all. It is used by dozen of thousands of people, Linux users of course, but also on Windows, OSX, BSDs… A flagship for Free Software, some would say. So clearly coding for GIMP can be scary and exciting in the same time. It won’t be the same as contributing to most smaller programs. But we are lucky: GIMP has a very sane and good quality code. Now let’s be clear: we have a lot of crappy pieces of code here and there, some untouched for years, some we hate to touch but have to sometimes. That will happen with any project this size. But overall, I really enjoy the quality of the code and it makes coding in GIMP somewhat a lot more enjoyable than in some less-cared projects I had to hack on in my life. This is also thanks to the maintainer, Mitch, who will bore you with syntax, spaces, tabs, but also by his deep knowledge of GIMP architecture. And I love this.

On the other hand, it also means that getting your patch into GIMP can be a littler more complicated than in some other projects. I saw a lot of projects which would accept patches in any state as long as it does more or less what it says it does. But nope, not in GIMP. It has to work, of course, but it also has to follow strict code quality, syntax-wise, but also architecture-wise. Also if your code touches the public API or the GUI, be ready for some lengthy discussions. But this is all worth it. Whether you are looking for improving an already awesome software, adding lines to your resume, improving your knowledge or experience on programming, learning, you will get something meaningful out of it. GIMP is not your random project and you will have reasons to be proud to be part of it.

How to choose a first bug?

Interested already? Have a look at bugs that we think are a good fit for newcomers! Now don’t feel obligated to start there. If you use GIMP and are annoyed by specific bugs or issues, this may well be a much better entrance. Personally I never contributed to fix a random bug as first patch. Every single first patch I did for Free Software was for an issue I experienced. And that’s even more rewarding!

Oh and if you happen to be a Windows or OSX developer, you will have an even bigger collection of bugs to look into. We are even more needing developer on non-Linux platforms, and that means we have a lot more bugs there, but also most likely a good half of these are probably easy to handle even for new developers.

Finally crashes and bugs which output warnings are often pretty easy since you can usually directly investigate them in a debugger (gdb for instance), which is also a good tool to learn if you never used. Bugs related to a graphical element, especially with text, are a good fit for new developers too since you can easily grep texts to search through the code.

Infrastructure

Now there are whole other areas where you could contribute. These are unloved area and less visible, which is sad. And I wish to change this. One of these is infrastructure! GIMP, as many big projects, have a website, build and continuous integration servers, wikis, mailing lists… These are time-consuming and have few contributors.

So we definitely welcome administrators. Our continuous integration regularly encounters issue. Well as we speak, the build fails, not because of GIMP, instead because minimum requirements for our dev environment are not met. At times, we have had a failing continuous integration for months. The problem is easy: we need more contributors to share the workload. Currently Sam Gleske is our only server administrator but as a volunteer, he has only limited time. We want to step up to next level with new people to co-administrate the servers!

Writers

While we got a new website recently (thanks to Patrick David especially!), more frequent news (here I feel we have to cite Alexandre Prokoudine too), we’d still welcome new hands. That could be yours!

We need documentation for GIMP 2.10 coming release, but also real good quality tutorials under Free/Libre licenses. The state of our tutorials on gimp.org were pretty sad before the new website, to say the least. Well now that’s pretty empty.

Of course translations are also a constant need too. GIMP is not doing too bad here, but if that’s what you like, we could do even better! For this, you will want to contact directly the GNOME translation team for your target language.

Designers

And finally my pet project, I repeat this often, but I think a lot of GIMP workflow would benefit from some designer view. If you are a UX designer and interested, be welcome to the team too!

So here it is. All the things which you could do with us. Don’t be scared. Don’t be a stranger. Instead of being this awesome project you use, it could be your awesome project. Make GIMP! 🙂

So this year was our first GUADEC, for both Aryeom (have a look at Aryeom’s report, in Korean) and I. GUADEC stands for “GNOME Users And Developers European Conference”, so as expected we met a lot of both users and developers of GNOME, the Desktop Environment we have been happily using lately (for a little more than a year now). It took place at the Karlsruhe Institute of Technology in Germany.

Apart from some people we knew from Libre Graphics Meeting events over the years, we met a lot of new faces, and that’s very cool. We have to spread ZeMarmot love, right?! 🙂

My first impression is the remarkable organization of GUADEC. They planned social events every day (barbecue, picnic with football, beer nights, dinners… even an ice cream truck at free price!), very well planned schedules, efficient sponsorship, workshops and hackfests, a cake for the 19th birthday… They know their geeks and we nearly never ran out of coffee (well, excepted during the hackfests ;-()!

GUADEC opens with a huge barbecue!GUADEC picnic

Of course, we were not here just for the beer, there were a lot of very cool talks. I was quite interested into Endless and their OS based on GNOME. It was interesting to see the design experiment around GNOME maps too. There were also a bunch of discussion relative to security, and definitely the project on everyone’s mouth was Flatpak. This is clearly a technology that a lot of people have been waiting for, and the center of many discussions.

But also the small feedback that we got on how the GNOME Foundation works was quite insightful. Obviously this is only a small piece of it, but being able to participate and view some of the decision process, discuss about the money that the foundation had been able to raise, how it should be used, about new events around GNOME (like LAS GNOME). This all felt like an exciting time and a cool community to be part of.

Another of my activities was trying to get designers interested into GIMP. For people who have followed my work a little, you know I have been really involved into getting GIMP a design revival (taking over the GUI wiki, creating an official GIMP GUI mailing list, trying to make other developers interested into this topic again and proposing some ideas here and there…), yet with very limited success so far (well I had some, but would really love if things could go forward at a better pace). I think GIMP is clearly a great software, both historically and technically. Historically because it is the root of several awesome technologies, like GTK+ (no GNOME without, right?) or lately GEGL, and because many people would call it a “flagship” for Free Software. But great technically as well: I am very amazed how good the code is. It has its zones of darkness (every software has, especially after more than 20 years of existence), because it is still well organized, clean, following clear coding standards with quality code. There is obviously a good technical maintainership. Now the GUI is less than perfect. Not because it is flawed, but because it follows here too 20-year-old design standards. Any software this age has this kind of problem, especially with design paradigms evolving faster and faster. Yet I believe a software that great deserves a chance to get a new face. So what’s the link to GUADEC? Well I have tried to approach various GNOME designers and getting them interested to GIMP again. If you are one of these designers I approached, hopefully I convinced you to give it a try. If I didn’t approach you, I may just not have known who you are, and do not hesitate to come to me. I am not saying that any complete huge redesign will happen overnight. But you definitely have open ears and we, at GIMP, are willing to discuss how to make a better user experience! We can start small.

Another reason for our presence was obviously to present our project: ZeMarmot. We were quite pleased to discover that some people knew about us. I was clearly going there thinking we would be like total strangers. But not only did some people recognize us, but we even had someone telling us his daughter was a huge fan. What? We got our first fan girl?

By the way, they had this badge machine, so while we were there, we printed and created our first hand-made badges of ZeMarmot. About 3 dozens of them. They are therefore quite exclusive so if you got some of them while being there, don’t throw them away!
Oh and by the way, that’s Creative Commons by-sa badges, like our movie! 😉

For people interested into our talk, here it is! You’ll see some quite exclusive contents with a few seconds of some cuts of the pilote. Enjoy!

And so here we are, ready to leave Germany. This was a very interesting event. We may come back next year, who knows? Only regret I have is that I was really hoping to participate to a workshop, but since our hotel was already booked, it was not made possible. Well next year maybe…

So thank you GNOME for the event and also for sponsoring our travel there! 🙂

While I have been working for days on the animation software for ZeMarmot, I wanted to “rest” my brain a little and came back to an old project of mine, which I should have implemented months ago.

So let’s get the troll out straight away: yes, this is about the split between save and export on GIMP. Now I was not there when the decision was taken, but I think it makes sense anyway. Saving is about “your work”, your process. XCF is — in such a view — not an image format, but a project format. It contains much more than the final visual image. Same as you would not save a “.mpeg“, “.avi” or “.mov” in blender, but a “.blend“, you don’t save a “.jpeg” or “.png” either, but a “.xcf” (another analogy for developers out there: “.blend” or “.xcf” can be compared to your source files — which is definitely what they are in a multimedia project — and the image or video formats as the compiled binary).

Yet I understand that some users have a hard time understanding this since there are nearly no difference in our GUI between saving and exporting.
What’s the difference, you’d ask? And you’d be right.

In the last 2 days, I refactored the whole GimpFileDialog code, which was completely mixing every concepts with hard-to-read if {} else {} statements inside a single class. GimpFileDialog became a generic parent class, containing only logics common to all file dialogs, and I added 3 specific children: GimpOpenDialog, GimpSaveDialog and GimpExportDialog.
This will allow us to do easily much more interesting graphical interfaces specific to each process.

As a proof of concept, I tested a “Scale at export” feature, which would allow to rescale images at export time, without touching the original. Who indeed never worked on some high resolution image, then needed to export it in lower resolution (to upload on some website, send through email or whatever…)? The current GUI would force to scale the original image, export it, then not forget to cancel the scale afterwards (if you forget, save and quit — for instance by habits — you are doomed: you just completely lost data and hours of high res work!).
Here for a UI test:

Now before you tell anything: I know that the above screenshot does not look so nice, with a lot of wasted space on the right. I reused an existing widget (the same used in the “Scale Image” dialog, if you know GIMP well) and have not been trying to customize for this first version. The goal was mostly to test the new refactored code and we have some more thinking and discussion before actually adding these features (there are many more things that could be rethought to improve export, at deeper levels too).
The refactoring is now merged to master; the “Scale at export” isn’t yet though (feel free to test it on its git feature branch though, it’s functional).

Of course this is only the start of greater things. One may want to crop an image, change the color space (particularly if you were working in non sRGB), or even apply any GEGL operation before export (like “sharpen” after downscaling).
This should all be possible soon. Of course we’d have to work on the ideal UI to not clutter the export dialog. I will keep readers updated for when the next steps will occur.

I believe this is partially what some people would call a “Save for Web” feature, though I personally don’t like this naming since it is far too restrictive. You may want to change your exported image for far many more reasons that just “the web”.